selftests/bpf: add a test case to check verifier pointer arithmetic (6ead18fb) · Commits · 戴 / test

tools/testing/selftests/bpf/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -13,7 +13,7 @@ LDLIBS += -lcap -lelf

		TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs

		TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o
		TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o

		TEST_PROGS := test_kmod.sh

tools/testing/selftests/bpf/test_progs.c

+16 −0

Original line number	Diff line number	Diff line
		@@ -268,6 +268,21 @@ out:
		bpf_object__close(obj);
		}

		static void test_tcp_estats(void)
		{
		const char *file = "./test_tcp_estats.o";
		int err, prog_fd;
		struct bpf_object *obj;
		__u32 duration = 0;

		err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
		CHECK(err, "", "err %d errno %d\n", err, errno);
		if (err)
		return;

		bpf_object__close(obj);
		}

		int main(void)
		{
		struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
		@@ -277,6 +292,7 @@ int main(void)
		test_pkt_access();
		test_xdp();
		test_l4lb();
		test_tcp_estats();

		printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt);
		return 0;

tools/testing/selftests/bpf/test_tcp_estats.c

0 → 100644

+258 −0

Original line number	Diff line number	Diff line
		/* Copyright (c) 2017 Facebook
		*
		* This program is free software; you can redistribute it and/or
		* modify it under the terms of version 2 of the GNU General Public
		* License as published by the Free Software Foundation.
		*/

		/* This program shows clang/llvm is able to generate code pattern
		* like:
		* _tcp_send_active_reset:
		* 0: bf 16 00 00 00 00 00 00 r6 = r1
		* ......
		* 335: b7 01 00 00 0f 00 00 00 r1 = 15
		* 336: 05 00 48 00 00 00 00 00 goto 72
		*
		* LBB0_3:
		* 337: b7 01 00 00 01 00 00 00 r1 = 1
		* 338: 63 1a d0 ff 00 00 00 00 (u32 )(r10 - 48) = r1
		* 408: b7 01 00 00 03 00 00 00 r1 = 3
		*
		* LBB0_4:
		* 409: 71 a2 fe ff 00 00 00 00 r2 = (u8 )(r10 - 2)
		* 410: bf a7 00 00 00 00 00 00 r7 = r10
		* 411: 07 07 00 00 b8 ff ff ff r7 += -72
		* 412: bf 73 00 00 00 00 00 00 r3 = r7
		* 413: 0f 13 00 00 00 00 00 00 r3 += r1
		* 414: 73 23 2d 00 00 00 00 00 (u8 )(r3 + 45) = r2
		*
		* From the above code snippet, the code generated by the compiler
		* is reasonable. The "r1" is assigned to different values in basic
		* blocks "_tcp_send_active_reset" and "LBB0_3", and used in "LBB0_4".
		* The verifier should be able to handle such code patterns.
		*/
		#include <string.h>
		#include <linux/bpf.h>
		#include <linux/ipv6.h>
		#include <linux/version.h>
		#include <sys/socket.h>
		#include "bpf_helpers.h"

		#define _(P) ({typeof(P) val = 0; bpf_probe_read(&val, sizeof(val), &P); val;})
		#define TCP_ESTATS_MAGIC 0xBAADBEEF

		/* This test case needs "sock" and "pt_regs" data structure.
		* Recursively, "sock" needs "sock_common" and "inet_sock".
		* However, this is a unit test case only for
		* verifier purpose without bpf program execution.
		* We can safely mock much simpler data structures, basically
		* only taking the necessary fields from kernel headers.
		*/
		typedef __u32 __bitwise __portpair;
		typedef __u64 __bitwise __addrpair;

		struct sock_common {
		unsigned short skc_family;
		union {
		__addrpair skc_addrpair;
		struct {
		__be32 skc_daddr;
		__be32 skc_rcv_saddr;
		};
		};
		union {
		__portpair skc_portpair;
		struct {
		__be16 skc_dport;
		__u16 skc_num;
		};
		};
		struct in6_addr skc_v6_daddr;
		struct in6_addr skc_v6_rcv_saddr;
		};

		struct sock {
		struct sock_common __sk_common;
		#define sk_family __sk_common.skc_family
		#define sk_v6_daddr __sk_common.skc_v6_daddr
		#define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
		};

		struct inet_sock {
		struct sock sk;
		#define inet_daddr sk.__sk_common.skc_daddr
		#define inet_dport sk.__sk_common.skc_dport
		__be32 inet_saddr;
		__be16 inet_sport;
		};

		struct pt_regs {
		long di;
		};

		static inline struct inet_sock inet_sk(const struct sock sk)
		{
		return (struct inet_sock *)sk;
		}

		/* Define various data structures for state recording.
		* Some fields are not used due to test simplification.
		*/
		enum tcp_estats_addrtype {
		TCP_ESTATS_ADDRTYPE_IPV4 = 1,
		TCP_ESTATS_ADDRTYPE_IPV6 = 2
		};

		enum tcp_estats_event_type {
		TCP_ESTATS_ESTABLISH,
		TCP_ESTATS_PERIODIC,
		TCP_ESTATS_TIMEOUT,
		TCP_ESTATS_RETRANSMIT_TIMEOUT,
		TCP_ESTATS_RETRANSMIT_OTHER,
		TCP_ESTATS_SYN_RETRANSMIT,
		TCP_ESTATS_SYNACK_RETRANSMIT,
		TCP_ESTATS_TERM,
		TCP_ESTATS_TX_RESET,
		TCP_ESTATS_RX_RESET,
		TCP_ESTATS_WRITE_TIMEOUT,
		TCP_ESTATS_CONN_TIMEOUT,
		TCP_ESTATS_ACK_LATENCY,
		TCP_ESTATS_NEVENTS,
		};

		struct tcp_estats_event {
		int pid;
		int cpu;
		unsigned long ts;
		unsigned int magic;
		enum tcp_estats_event_type event_type;
		};

		/* The below data structure is packed in order for
		* llvm compiler to generate expected code.
		*/
		struct tcp_estats_conn_id {
		unsigned int localaddressType;
		struct {
		unsigned char data[16];
		} localaddress;
		struct {
		unsigned char data[16];
		} remaddress;
		unsigned short localport;
		unsigned short remport;
		} __attribute__((__packed__));

		struct tcp_estats_basic_event {
		struct tcp_estats_event event;
		struct tcp_estats_conn_id conn_id;
		};

		struct bpf_map_def SEC("maps") ev_record_map = {
		.type = BPF_MAP_TYPE_HASH,
		.key_size = sizeof(__u32),
		.value_size = sizeof(struct tcp_estats_basic_event),
		.max_entries = 1024,
		};

		struct dummy_tracepoint_args {
		unsigned long long pad;
		struct sock *sock;
		};

		static __always_inline void tcp_estats_ev_init(struct tcp_estats_event *event,
		enum tcp_estats_event_type type)
		{
		event->magic = TCP_ESTATS_MAGIC;
		event->ts = bpf_ktime_get_ns();
		event->event_type = type;
		}

		static __always_inline void unaligned_u32_set(unsigned char to, __u8 from)
		{
		to[0] = _(from[0]);
		to[1] = _(from[1]);
		to[2] = _(from[2]);
		to[3] = _(from[3]);
		}

		static __always_inline void conn_id_ipv4_init(struct tcp_estats_conn_id *conn_id,
		__be32 saddr, __be32 daddr)
		{
		conn_id->localaddressType = TCP_ESTATS_ADDRTYPE_IPV4;

		unaligned_u32_set(conn_id->localaddress.data, (__u8 *)saddr);
		unaligned_u32_set(conn_id->remaddress.data, (__u8 *)daddr);
		}

		static __always_inline void conn_id_ipv6_init(struct tcp_estats_conn_id *conn_id,
		__be32 saddr, __be32 daddr)
		{
		conn_id->localaddressType = TCP_ESTATS_ADDRTYPE_IPV6;

		unaligned_u32_set(conn_id->localaddress.data, (__u8 *)saddr);
		unaligned_u32_set(conn_id->localaddress.data + sizeof(__u32),
		(__u8 *)(saddr + 1));
		unaligned_u32_set(conn_id->localaddress.data + sizeof(__u32) * 2,
		(__u8 *)(saddr + 2));
		unaligned_u32_set(conn_id->localaddress.data + sizeof(__u32) * 3,
		(__u8 *)(saddr + 3));

		unaligned_u32_set(conn_id->remaddress.data,
		(__u8 *)(daddr));
		unaligned_u32_set(conn_id->remaddress.data + sizeof(__u32),
		(__u8 *)(daddr + 1));
		unaligned_u32_set(conn_id->remaddress.data + sizeof(__u32) * 2,
		(__u8 *)(daddr + 2));
		unaligned_u32_set(conn_id->remaddress.data + sizeof(__u32) * 3,
		(__u8 *)(daddr + 3));
		}

		static __always_inline void tcp_estats_conn_id_init(struct tcp_estats_conn_id *conn_id,
		struct sock *sk)
		{
		conn_id->localport = _(inet_sk(sk)->inet_sport);
		conn_id->remport = _(inet_sk(sk)->inet_dport);

		if (_(sk->sk_family) == AF_INET6)
		conn_id_ipv6_init(conn_id,
		sk->sk_v6_rcv_saddr.s6_addr32,
		sk->sk_v6_daddr.s6_addr32);
		else
		conn_id_ipv4_init(conn_id,
		&inet_sk(sk)->inet_saddr,
		&inet_sk(sk)->inet_daddr);
		}

		static __always_inline void tcp_estats_init(struct sock *sk,
		struct tcp_estats_event *event,
		struct tcp_estats_conn_id *conn_id,
		enum tcp_estats_event_type type)
		{
		tcp_estats_ev_init(event, type);
		tcp_estats_conn_id_init(conn_id, sk);
		}

		static __always_inline void send_basic_event(struct sock *sk,
		enum tcp_estats_event_type type)
		{
		struct tcp_estats_basic_event ev;
		__u32 key = bpf_get_prandom_u32();

		memset(&ev, 0, sizeof(ev));
		tcp_estats_init(sk, &ev.event, &ev.conn_id, type);
		bpf_map_update_elem(&ev_record_map, &key, &ev, BPF_ANY);
		}

		SEC("dummy_tracepoint")
		int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
		{
		if (!arg->sock)
		return 0;

		send_basic_event(arg->sock, TCP_ESTATS_TX_RESET);
		return 0;
		}

		char _license[] SEC("license") = "GPL";
		__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */

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